1. Field of the Invention
The present invention relates to an electric bending endoscope which electrically bends a bending portion arranged to a distal-end portion of an inserting portion.
2. Description of the Related Art
Recently, an endoscope is widely used. Various curing treatments are performed by inserting an elongated inserting portion in the body cavity so as to observe the organ in the body cavity or by using a therapeutic instrument inserted in a channel dedicated to the therapeutic instrument as needed. In the industrial field, the endoscope observes and examines inner scratches and corrosion of a steam generator, a turbine, an engine and a chemical plant by inserting the elongated inserting portion.
The endoscope has a bending portion which is freely bendable connected to a proximal-end side of a distal-end portion of the elongated inserting portion. The endoscope receives an instruction as to the bending amount which corresponds to a bending direction or a bending speed of the bending portion, by inputting means for a bending operation such as a bending operation lever or a joystick device arranged to an operating portion. In the endoscope, a bending operation wire is mechanically stretched and contracted based on the bending amount inputted as the instruction so as to bend the bending portion.
The above-mentioned endoscope contains an electric bending driving system, that is, electric bending endoscope, in which a motor as bending driving means included in the endoscope is electrically rotation-controlled, the driving force of the motor contracts and stretches the bending operation wire, and the bending portion is bent.
For example, Japanese Unexamined Patent Application Publication No. 6-63010 discloses an endoscope, in which a pad arranged like a cross as bending operation input means performs the operation for instructing the bending. Further, Japanese Unexamined Patent Application Publication No. 6-304126 discloses a joystick or the like as the bending operation input means.
In the electric bending endoscope having the above-mentioned bending operation input means, in the case of an endoscope which is not electrically operated but performs the bending operation by manually rotating a bending operation knob, the bending operation does not need to be executed with large-force rotation and the operability is improved.